阅读说明：本技术 一种利用超临界流体渗透溶解能力对煤脱硫脱灰实验方法 (Coal desulfurization and deliming experimental method utilizing supercritical fluid osmotic dissolution capacity ) 是由 刘晋芳 桂夏辉 彭垠 巩林盛 赵铁柱 张鹏德 马子鉴 于 2019-11-21 设计创作，主要内容包括：本发明公开了一种利用超临界流体渗透溶解能力对煤脱硫脱灰实验方法,涉及煤炭燃前脱硫领域。本发明以超临界流体技术为核心工艺,主要是通过温度和压力的调节,溶质在超临界CO<Sub>2</Sub>中的溶解度与超临界CO<Sub>2</Sub>的密度有关,而温度和压力共同决定CO<Sub>2</Sub>的密度,通过改变温度和压力条件,使CO<Sub>2</Sub>在超临界状态有着特殊能力,有选择性的溶解和分离,对煤中有机硫进行脱除,在有效降低有机硫的同时,进一步起到了大幅度降灰的效果。整套工艺流程简单,操作方便,容易实现温度和压力的控制,适合大型工业化；同时CO<Sub>2</Sub>对原料无毒无污染,并对煤质无影响；脱硫率：有机硫能够脱除23%,无机硫能够脱出70%,同时灰分降低32%。(The invention discloses an experimental method for desulfurization and deashing of coal by utilizing the osmotic dissolution capacity of a supercritical fluid, and relates to the field of desulfurization before combustion of coal. The invention takes supercritical fluid technology as a core process, and the solute is in supercritical CO mainly through the regulation of temperature and pressure 2 Medium solubility and supercritical CO 2 Is related to the density of (A), and the temperature and pressure together determine the CO 2 By changing the temperature and pressure conditions, CO 2 The organic sulfur in coal is removed by selective dissolution and separation in a supercritical state, so that the organic sulfur is effectively reduced, and the effect of greatly reducing ash is further achieved. The whole process flow is simple, the operation is convenient, the control of temperature and pressure is easy to realize, and the method is suitable for large-scale industrialization; with CO 2 The raw materials are nontoxic and pollution-free, and the coal quality is not influenced; desulfurization degree: organic sulfur can be removed by 23 percent, and inorganic sulfur can be removed70% of the ash is removed, and the ash content is reduced by 32%.)

1. A coal desulfurization and deliming experimental method by utilizing the penetration and dissolution capacity of supercritical fluid is characterized in that: the method comprises the following steps:

(1) pretreating the sample: crushing a coal sample to a certain granularity;

(2) removing air and impurities in the kettle body: adopting a full-boring quick-opening cover type reaction kettle, opening inlet and outlet valves of the extraction kettle to connect with a supercritical fluid storage container, and using supercritical CO₂Circulating the whole closed system by fluid circulation, cleaning the pipeline by carrying ethanol through an auxiliary pump, and closing an outlet valve of the extraction kettle to ensure good air tightness;

(3) canning materials: filling the coal sample obtained in the step (1) into a full-boring quick-opening cover type reaction kettle, and screwing the whole kettle cover serving as a large bolt into a seal;

(4) desulfurization experiment:

① regulating temperature and pressure SC-CO₂In the process flow, the supercritical fluid CO is adjusted by adjusting the temperature and pressure parameters in the extraction kettle₂To the critical point of the supercritical fluid, and then changing the conditions of temperature and pressure to make CO₂Dissolving and separating the removed material in a supercritical state;

② separating the fluid from solute by dissolving and eliminating organic and inorganic sulfur from coal sample in extraction kettle in supercritical fluid, eliminating inorganic sulfur and lowering ash content, and reducing pressure to make CO fluid₂Separating the organic solute from the organic solute to complete the whole desulfurization and ash reduction process;

③ energy-saving pressure-reducing heat exchange, in the separation stage in the separation kettle, supercritical fluid CO is obtained by energy-saving pressure reduction and temperature regulation in the heat exchanger₂All become gas, and the removed organic sulfur is separated into liquid phase and precipitated at the bottom of the separator, and CO is discharged₂The gas is discharged through a pipeline or recycled through a cooling system;

(5) sample collection and subsequent processing: after the experiment is finished, closing the air inlet valve, opening the air outlet valve, slowly releasing the gas in the extraction kettle, removing the gas circuit connection, closing the heating key, and cooling; opening the extraction kettle and sampling; and soaking the reacted coal sample in acetone for a certain time, further extracting, washing with deionized water, and drying to test the sample.

2. The method for removing organic sulfur in coal by supercritical fluid hydrogenation reaction according to claim 1, wherein: the granularity of the coal sample in the step (1) is 1-3mm or 3-6 mm.

3. The method for removing organic sulfur in coal by supercritical fluid hydrogenation reaction according to claim 1, wherein: in the step (4), the temperature and pressure ranges are adjusted to enable CO to react₂Heating the gas to above critical point at 35-40 deg.C under 7-10 MPa.

Technical Field

The invention relates to the field of coal desulfurization before combustion, in particular to an experimental method for desulfurization and deashing of coal by utilizing the osmotic dissolving capacity of a supercritical fluid.

Background

China has abundant coal resources and is the biggest world coal producing and consuming country, but sulfur-containing substances in coal release high-concentration SO to the atmosphere in the combustion process₂Harmful gases have adverse effects on human health and growth of animals and plants, and emissions after combustion cause a series of environmental problems such as air pollution, acid rain, climate change and the like, so how to desulfurize coal before combustion needs to be solved urgently.

The inorganic sulfur in the coal can be effectively removed by a physical method, and the process of gravity separation and deashing is accompanied with the removal of the inorganic sulfur. But the organic sulfur component is complex, and the sulfur has thioether and thiol aliphatic structure sulfur, thiophene, sulfone and sulfoxide conjugated structure sulfur, the existing desulfurization method such as physical washing technology is widely and economically applied, but only inorganic sulfur can be removed; biological and chemical methods can remove inorganic sulfur, but can only remove partial aliphatic organic sulfur, the removal effect on sulfur with macromolecular conjugated structure is not obvious, the production cost is high, and the method has a large difference from industrial application; the gasification and liquefaction of coal are further researched and perfected, and the technology is not enough to be formed. However, as the coal density increases, the content of organic sulfur such as thioether and mercaptan fatty structures decreases, and the content of organic sulfur such as thiophene and (sulfoxide) increases, so that the difficulty in removing organic sulfur further increases. The prior method adopted in the field of pre-combustion desulfurization has the following problems: (1) the organic sulfur in the coal cannot be removed greatly; (2) the process is complex, the cost is high, and large-scale industrialization cannot be realized; (3) some methods adopt the desulfurization auxiliary agent to change the coal quality characteristics of the coal in the coal treatment process, or remove the used medicament again after removing the sulfur component, and the process is complex. Therefore, how to effectively remove the organic sulfur which is a complex component in the coal is an important difficult problem to be solved urgently.

Disclosure of Invention

The invention provides an experimental method for desulfurization and deashing of coal by utilizing the osmotic dissolving capacity of a supercritical fluid, aiming at solving the problem of removal of organic sulfur as a complex component in the coal.

The invention is realized by the following technical scheme: a coal desulfurization and deliming experimental method utilizing the penetration and dissolution capacity of supercritical fluid comprises the following steps:

(1) pretreating the sample: crushing a coal sample to a certain granularity;

(2) removing air and impurities in the kettle body: adopting a full-boring quick-opening cover type reaction kettle, opening inlet and outlet valves of the extraction kettle to connect with a supercritical fluid storage container, and using supercritical CO₂Circulating the whole closed system by fluid circulation, cleaning the pipeline by carrying ethanol through an auxiliary pump, and closing an outlet valve of the extraction kettle to ensure good air tightness;

(3) canning materials: filling the coal sample obtained in the step (1) into a full-boring quick-opening cover type reaction kettle, and screwing the whole kettle cover serving as a large bolt into a seal;

(4) desulfurization experiment:

① regulating temperature and pressure SC-CO₂In the process flow, the supercritical fluid CO is adjusted by adjusting the temperature and pressure parameters in the extraction kettle₂The density of the supercritical fluid is reached, and then the conditions of temperature and pressure are changed,make CO₂Dissolving and separating the removed material in a supercritical state;

② separating the fluid from solute by dissolving and eliminating organic and inorganic sulfur from coal sample in extraction kettle in supercritical fluid, eliminating inorganic sulfur and lowering ash content, and reducing pressure to make CO fluid₂Separating the organic solute from the organic solute to complete the whole desulfurization and ash reduction process;

③ energy-saving pressure-reducing heat exchange, in the separation stage in the separation kettle, supercritical fluid CO is obtained by energy-saving pressure reduction and temperature regulation in the heat exchanger₂All become gas, and the removed organic sulfur is separated into liquid phase and precipitated at the bottom of the separator, and CO is discharged₂The gas is discharged through a pipeline or recycled through a cooling system;

(5) sample collection and subsequent processing: after the experiment is finished, closing the air inlet valve, opening the air outlet valve, slowly releasing the gas in the extraction kettle, removing the gas circuit connection, closing the heating key, and cooling; opening the extraction kettle and sampling; and soaking the reacted coal sample in acetone for a certain time, further extracting, washing with deionized water, and drying to test the sample.

The invention takes supercritical fluid technology as a core process, and the solute is in supercritical CO mainly through the regulation of temperature and pressure₂Medium solubility and supercritical CO₂Is related to the density of (A), and the temperature and pressure together determine the CO₂By changing the temperature and pressure conditions, CO₂Has special capacity of selective dissolution and separation in a supercritical state. The method has the advantages of effectively reducing organic sulfur and simultaneously further playing a role in greatly reducing ash for removing the organic sulfur in the coal. The whole process flow is simple, the operation is convenient, the control of temperature and pressure is easy to realize, and the method is suitable for large-scale industrialization. With CO₂Has no toxicity and pollution to raw materials and has no influence on coal quality. The CO2 has high dissolving capacity and penetrating capacity to the removed substances in a supercritical state and low dissolving capacity and penetrating capacity in a non-supercritical state. The fluid can penetrate into the coal under supercritical stateThe organic solute in the gaps is selectively dissolved and seeped out of the gaps as a carrier of the organic solute, and the organic solute is rapidly condensed, so that the whole separation process is realized. The invention adopts a full-boring quick-opening cover type reaction kettle, so as to meet the requirement of frequently loading and unloading solid materials under the high-pressure condition; supercritical fluid CO₂Supercritical CO₂The fluid has the characteristics of low viscosity, good mass transfer, good diffusivity and compressibility and the like, and has better dissolving capacity on a solvent with stronger polarity, so that CO₂The extraction solvent is preferably safe, energy-saving and pollution-free.

Preferably, the coal sample in the step (1) has a particle size of 1-3mm or 3-6mm, and the particle size is in a range suitable for dissolving and separating organic sulfur in the coal.

Preferably, in step (4), the temperature and pressure ranges are adjusted to introduce CO₂Heating the gas to above critical point at 35-40 deg.C under 7-10 MPa.

Compared with the prior art, the invention has the following beneficial effects: the invention provides an experimental method for desulfurization and deliming of coal by utilizing the osmotic dissolving capacity of a supercritical fluid, which comprises the following steps: (1) the organic sulfur and the inorganic sulfur in the coal can be greatly removed, the organic sulfur can be removed by 23 percent, the inorganic sulfur can be removed by 70 percent, and simultaneously the ash content is reduced by 32 percent; (2) simple process, easy control of temperature and pressure, low cost, and CO₂The product is easy to purchase, low in price and recyclable, and can realize large-scale industrialization; (3) some methods adopt the desulfurization auxiliary agent to change the coal quality characteristics of the coal in the coal treatment process, or remove the used medicament again after removing the sulfur component, and the process is complex, but the method adopts CO₂No pollution and residue to the product, and no subsequent treatment.

Drawings

FIG. 1 is a process flow diagram of the present invention.

FIG. 2 is a flow chart of the apparatus of the present invention.

Detailed Description

The present invention is further illustrated by the following specific examples.

An experimental method for desulfurization and deliming of coal by using osmotic dissolution capacity of supercritical fluid is shown in figures 1 and 2 and comprises the following steps:

(1) pretreating the sample: crushing a coal sample to a certain granularity, wherein the granularity of the coal sample is 1-3mm or 3-6 mm;

(2) removing air and impurities in the kettle body: adopting a full-boring quick-opening cover type reaction kettle, opening inlet and outlet valves of the extraction kettle to connect with a supercritical fluid storage container, and using supercritical CO₂Circulating the whole closed system by fluid circulation, cleaning the pipeline by carrying ethanol through an auxiliary pump, and closing an outlet valve of the extraction kettle to ensure good air tightness;

(3) canning materials: filling the coal sample obtained in the step (1) into a full-boring quick-opening cover type reaction kettle, and screwing the whole kettle cover serving as a large bolt into a seal;

(4) desulfurization experiment:

① regulating temperature and pressure SC-CO₂In the process flow, the supercritical fluid CO is adjusted by adjusting the temperature and pressure parameters in the extraction kettle₂To the critical point of the supercritical fluid, and then changing the conditions of temperature and pressure to make CO₂Dissolving and separating the removed material in a supercritical state;

② separating the fluid from solute by dissolving and eliminating organic and inorganic sulfur from coal sample in extraction kettle in supercritical fluid, eliminating inorganic sulfur and lowering ash content, and reducing pressure to make CO fluid₂Separating the organic solute from the organic solute to complete the whole desulfurization and ash reduction process;

③ energy-saving pressure-reducing heat exchange, in the separation stage in the separation kettle, supercritical fluid CO is obtained by energy-saving pressure reduction and temperature regulation in the heat exchanger₂All become gas, and the removed organic sulfur is separated into liquid phase and precipitated at the bottom of the separator, and CO is discharged₂The gas is discharged through a pipeline or recycled through a cooling system;

(5) sample collection and subsequent processing: after the experiment is finished, closing the air inlet valve, opening the air outlet valve, slowly releasing the gas in the extraction kettle, removing the gas circuit connection, closing the heating key, and cooling; opening the extraction kettle and sampling; and soaking the reacted coal sample in acetone for a certain time, further extracting, washing with deionized water, and drying to test the sample.

This example uses the same high-grade coal and SC-CO₂The method comprises the following steps:

(1) pretreating the sample: crushing a coal sample to a certain granularity, wherein the granularity of the coal sample is 1-3mm or 3-6 mm;

(2) removing air and impurities in the kettle body: adopting a full-boring quick-opening cover type reaction kettle, opening inlet and outlet valves of the extraction kettle to be connected with a supercritical fluid storage container, and checking CO₂The outlet pressure of the steel cylinder is ensured to be 5-6 MPa, and supercritical CO is used₂Circulating the whole closed system by fluid circulation, simultaneously observing a gas pressure gauge beside the closed system, carrying an ethanol cleaning pipeline through an auxiliary pump, closing an outlet valve of the extraction kettle, and ensuring the complete air tightness;

(3) canning materials: filling the coal sample obtained in the step (1) into a full-boring quick-opening cover type reaction kettle, and screwing the whole kettle cover serving as a large bolt into a seal; putting the weighed sample into a charging barrel, and putting the sample into the charging barrel, wherein the raw material is not too full (according to the product process), and is generally 2-3 cm away from an upper filter screen; putting a white plastic O-shaped sealing ring; placing a sintered steel perforated plate; putting and screwing a stainless steel pressing ring with threads; a special handle is used for placing the charging barrel into a charging barrel cavity of a 1L extraction kettle in the main machine;

(4) desulfurization experiment: the water in each circulating water tank in the device is heated by an electric heating pipe and then is conveyed by a circulating pump for heating and constant temperature of an extraction kettle and a separation kettle; and checking whether the cooling water source is unblocked (relative to the water cooling unit), wherein the cooling box is filled with 30% glycol water solution:

① regulating temperature and pressure SC-CO₂In the process flow, the supercritical fluid CO is adjusted by adjusting the temperature and pressure parameters in the extraction kettle₂To the critical point of the supercritical fluid, and then changing the conditions of temperature and pressure to make CO₂Dissolving and separating in supercritical stateA material to be removed; observing and adjusting corresponding valves at any time to keep the pressure of the extraction kettle and the separation kettle in accordance with the specified requirements until the extraction time required by the test is reached;

② separating the fluid from solute by dissolving and eliminating organic and inorganic sulfur from coal sample in extraction kettle in supercritical fluid, eliminating inorganic sulfur and lowering ash content, and reducing pressure to make CO fluid₂Separating the organic solute from the organic solute to complete the whole desulfurization and ash reduction process;

③ energy-saving pressure-reducing heat exchange, in the separation stage in the separation kettle, supercritical fluid CO is obtained by energy-saving pressure reduction and temperature regulation in the heat exchanger₂All become gas, and the removed organic sulfur is separated into liquid phase and precipitated at the bottom of the separator, and CO is discharged₂The gas is discharged through a pipeline or recycled through a cooling system;

(5) sample collection and subsequent processing: after the experiment is finished, the running of the refrigerator pump is stopped and the CO is stopped by pressing the STOP button in the digital operator₂The plunger pump (high-pressure pump) runs, the heating switches of the circulating heating water tanks are closed, the heating and the circulation of the circulating water tanks are stopped, the air inlet valve is closed, the air outlet valve is opened, the gas in the extraction kettle is slowly released, the gas path connection is removed, the heating key is closed, and the extraction kettle is cooled; opening the extraction kettle and sampling; and soaking the reacted coal sample in acetone for a certain time, further extracting, washing with deionized water, and drying to test the sample.

According to the comparison of the data after the reaction and the original data, the sulfur content and the ash content in the coal are obviously reduced, and the caking property and the calorific value are basically unchanged, which shows that the method does not influence the original coal quality while effectively separating the organic sulfur.

The following comparative experiments were carried out with varying temperature, pressure, and treatment time, and the results are shown in Table 1:

TABLE 1

The scope of the invention is not limited to the above embodiments, and various modifications and changes may be made by those skilled in the art, and any modifications, improvements and equivalents within the spirit and principle of the invention should be included in the scope of the invention.